Sheet stacking apparatus

ABSTRACT

Apparatus for stacking copies from documents that are copied in repeated cycles. A transport delivers copies to a gate which collects them in a stack. A jogging device positioned at the entrance of the gate ensures proper corner registration of the copies in the tray. After the stack is assembled in the gate, the gate is pivoted out of the sheet path and pinch rolls associated with the gate serve to grip the stack and eject it into a receiving tray located below the gate. Cam actuated devices serve to reposition the gate and pinch rolls at the proper interval.

United States Patent 11 1 Korn et al.

1 March 6, 1973 SHEET STACKING APPARATUS [75] Inventors: Homer Korn, Webster; Stephen J. Greenfield; Denis J. Stemmle, both of Fairport, all of NY.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: Sept. 9, 1970 [21] Appl. No.& 70,831

[52] U.S. Cl ..198/35, 214/6 S [5| Int. Cl ..B65g 57/00 [58] Field of Search ..l98/3.5; 214/6 S; 271/89, 87

[561 References Cited UNITED STATES PATENTS 3,382,966 5/1968 Califano et al ..2l4/6 S 3,231,100 1/1966 Faeber ..214/6 S Primary Examiner-Even C. Blunk Assistant Examiner-Douglas D. Watts Attorney-James J. Ralabate, Norman E. Schrader and Melvin A. Klein 57 ABSTRACT Apparatus for stacking copies from documents that are copied in repeated cycles. A transport delivers copies to a gate which collects them in a stack. A jogging device positioned at the entrance of the gate ensures proper corner registration of the copies in the tray. After the stack is assembled in the gate, the gate is pivoted out of the sheet path and pinch rolls associated with the gate serve to grip the stack and eject it into a receiving tray located below the gate. Cam actuated devices serve to reposition the gate and pinch rolls at the proper interval.

5 Claims, 15 Drawing Figures PATENTEDHAR 6 I SHEET 10F 9 INVENTORS, KgR N GREENFlELD STENMLE ATTORNE V PATENTED 61075 SHEET 2 BF 9 PATENTED R 6 i 75 SHEET 30F 9 PATENTED MAR 1 75 SHEET 0F 9 PATENTED 61975 3, 7 1 9,266

SHEET 5 OF 9 FIG. 5

PATENTEDHAR 6W3 SHEET 6 OF FIG. 7

PATENTEBMAR sum 3,719,266

SHEET 70F 9 PATENIEUHA 5 ma SHEET 8 OF 9 FIG. [3

FIG. I2

F I6. I4

SHEET STACKING APPARATUS This invention relates to apparatus for assembling copies into stacks corresponding to documents copied automatically in repeated cycles or manually one at a time.

As is well known in the art of bookmaking, it is generally necessary to gather groups of different sheets placed in a definite order referred to as collating. The operation of assembling the sheets into sets or booklets normally consists of taking one sheet from each of a group of stacks and putting the sheets together in the order desired.

Normally, the assembling of the sheets into booklets is done by hand and is slow and cumbersome. Also, the number of people necessary is considerable and the likelihood of making a mistake great.

Present devices for assembling sheets into booklet form have the disadvantage of being prolix and costly and are not entirely satisfactory.

The present invention enables automatically delivering the copy sheets in set form. To accomplish this, a transport transports the copy sheets into an intermediate tray which collects them .into a stack. A jogging device positioned at the entrance of the tray ensures proper corner registration of the copies in the tray. After the stack, isassembled in the tray, the tray is pivoted out of the sheet path "and pinch r'olls associated with the tray serve to grip the stack and eject it into a collecting zone located below the tray. The tray is maintained out of the sheet path when stacking is not desired.

It is therefore an object of the present invention to improve the printing of books.

It is another object of the present invention to produce collated sets of copy sheets printed from a processor in a manner more simple and cheaper heretofore.

It is another object of the present invention to collate copy sheets from a processor into separately identifiable sets or stacks.

It is another object of the present invention to provide apparatus for stacking copies produced from a processor according to a document input being reproduced.

It is another object of the present invention to provide apparatus for stacking copy sheet material into books or alternatively receiving sheet material processed one at a time.

These objects as well as others will become more apparent upon considering the following description which is to be read in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a copying machine incorporating finishing apparatus according to the present invention;

FIG. 2 is a schematic side elevation of the various components of the copying machine employing the apparatus of the present invention;

FIG. 3 is an end view of the finishing apparatus according to the present invention;

FIG. 4 is a side sectional view of the finishing apparatus;

FIGS. 5 and 6 are end and side views respectively of the set separation assembly of the finishing apparatus;

FIGS. 7 and 8 are side views of the set ejection assembly illustrating different sequences in the operation thereof;

FIGS. 9 and 10 are end and side views of the clutch mechanism for the set ejection assembly;

FIG. 11 is a side view of the drive mechanism of the finishing apparatus;

FIGS. 12 and 13 are left and right hand end views of the drive mechanism;

FIG. 14 is a partial exploded isometric view illustrating the separated sets of copies in the output tray; and FIG. 15 is a schematic wiring diagram of the control circuit for the finishing apparatus.

GENERAL Illustrated in FIG. 1 is an exterior of an automatic xerographic reproducing machine 10 capable of producing either simplexed or duplexed copies in sets from a wide variety of originals which may be advanced in recirculating fashion by recirculating document apparatus 12 described in copending application Ser. No. 781,287, filed on Dec. 4, 1968, entitled Document Feed Apparatus and commonly assigned with the present invention. Although the present invention is particularly well suited for use in automatic xerography, the finishing apparatus generally designated 14 is equally well adapted for use in any number of devices in which cut sheets of material are delivered in a set or stack and the set then separated from a previous set and forwarded to an output tray. It should become apparent from the discussion below that this apparatus is not necessarily limited to its application to the particular embodiment shown herein.

For a general understanding of the automatic xerographic machine with which the present invention is utilized, reference is made to FIG. 2 which shows the various components of a typical xerographic processor. The processor includes a photosensitive plate including a photoconductive layer that is placed over a conductive backing. The plate is formed in the shape of a drum 15 and the drum mounted on a shaft 17 that is journaled for rotation in the machine frame. Basically, the xerographic drum is rotated in the direction indicated so as to pass sequentially through a series of xerographic processing stations. The photosensitive drum and the xerographic processing apparatus are driven at predetermined speeds relative to each other from a single drive system (not shown) and the operations thereof coordinated in order to produce proper cooperation of the various processing mechanisms.

The document to be reproduced is transported by document handling apparatus 12 from the bottom of a stack to a transparent horizontally supported platen l8 and scanned by means of a moving optical scanning system to produce a flowing light image. After scan the document is returned and the next advanced and scanned and so on until the entire document stack has been copied at which time the cycle may be repeated as described in the above copending application. The scanning system includes an elongated horizontal extended aperture lamp 25 and a movable lens element 28. The lamp and lens element moves in coordination across the object supported upon the platen to focus successive incremental bands of illumination reflected from the object onto the moving drum surface at synchronous speeds therewith. The optical path is folded by means of a pair of image mirrors 19 and 20 interposed between the lens and the drum surface and arranged to place the image on the drum at exposure station B. Prior to the imaging of the drum surface, the drum is first uniformly charged by means of a corona generator 29 positioned in charging station A. Under the influence of the flowing light image, the uniformly charged photoconductive surface is selectively dissipated in the non-imaged areas to form what is commonly known as a latent electrostatic image."

The latent electrostatic image is carried on the drum surface from the exposure station into the developing station C. The developing station primarily is comprised of a developer housing 32 adapted to support a supply of two-component developer material 31 therein. The developer material is transported by means of a bucket system 33 from the bottom of the developer housing to an elevated position where the material is delivered into the active development zone. The developer material is caused to flow downwardly in contact with the upwardly moving drum surface under closely controlled conditions wherein charged toner particles are attracted from the developer mix into the image areas on the plate surface, thus, making the image visible.

The moving drum surface next transports the developed xerographic image to a transfer station D. Cut sheets of final support material are also moved into the transfer station from sheet registering apparatus 34 in synchronous relation with the image on the drum surface. In the transfer station, the back side of the copy sheet is sprayed with an ion discharge from a transfer corotron 35 inducing on the sheet a charge having a polarity and magnitude sufficient to attract the toner material from the drum surface to the final support material. This induced charge also electrostatically tacks the final support material to the drum surface. In order to remove the copy sheet from the drum surface, a stripper finger 38 is positioned downstream from the transfer corotron. The finger is arranged to move between the drum surface and the copy sheet and lifts the sheet from the drum surface. The stripped sheet is directed along a predetermined path of travel into contact with a stationary vacuum transport 39.

Although a preponderance of the toner material is transferred from the drum surface to the copy sheet during the transfer process, invariably some residual toner remains behind on the drum surface after transfer. This residual toner is transported on the drum surface into a cleaning station E where it is brought under the influence of cleaning corotron 40 adapted to neutralize the electrostatic charge tending to hold the residual toner to the drum surface. The neutralized toner is mechanically cleaned from the drum surface by means of a brush or the like and the toner collected within a housing 41. A conveyor moving in an endless loop through tubes 42 transport the collected residual toner back to the developer housing where it is deposited within the developer mix so that it can be once again reused in the xerographic developing process.

The copy sheet, which has been removedfrom the drum surface after the transfer operation, ismoved along stationary transport 39 into fusing station F. The

fuser 43 is basically made up of an upper fuser roll 44 and a lower fuser roll 45 mounted in operative relation to each other and arranged to coact so as to support a sheet of material in pressure driving contact therebetween. The outer surface of the lower roll is heated by means of a horizontally supported radiant heat source 48 positioned in close proximity to the roll surface adjacent to the point at which the roll contacts the image bearing support material. As the heated roll is rotated in the direction indicated, the heated surface of the lower roll is pressed into intimate contact with the image face of the support sheet. Mechanical and heat energy is transported from the roll surface to the support sheet to permanently bond the toner particles to the support material.

Upon leaving the fuser, the fixed copy sheet is passed through a curvilinear sheet guide system, generally referred to as 49, into cooperating advancing rolls 50 and 51. The advancing rolls forward the sheets through a linear sheet guide system 52 into a second pair of advancing rolls 53 and 54. At this point, depending on whether simplex or duplex copies are desired, the simplexed copy sheet is either forwarded directly into finishing apparatus 14 or into upper supply tray 55 by means of a movable sheet guide 56 before the finishing apparatus for the duplexed copy. Movable sheet guide 56, and associated advancing rolls are prepositioned by appropriate machine logic system to direct the individual sheets into the desired path.

It is believed that the foregoing description is sufficient for purposes of the present application to show the general operation of a simplex or duplex xerographic reproducing machine embodying the teachings of the present invention. For a more detailed explanation of the the processing stations, reference is made to copending application Ser. No. 838,791, filed on July 3, 1969, and commonly assigned with the instant application.

FINISHING APPARATUS The transport assembly 60 receives copy sheet material from the processing station and includes two sets of pinch rolls 6], 62, 63 and 64 which advances the sheet material to an intermediate tray assembly 65. Intermediate tray assembly 65 comprises inner and outer baffle members 66 and 67 which serve to guide the sheet material which is arrested at the lowermost portion of the intermediate tray assembly by a gate 69. It will be noted that baffle members 66 and 67 are arranged to receive the sheet material with the topmost sheet on the outside and the subsequent sheets in an order which maintains a proper sequence with the document input.

In order to provide side registration of the sheet edges and registration of the lead edges of the sheet material, a jogger assembly 70 is provided to contact the sheet material received by the intermediate assembly. Jogger assembly.70 comprises a hub 71 on which are mounted a plurality of blades 73 made of flexible elastomeric material, such as rubber. The hub is rotated on a shaftinclined at an acute angle to the sheet path with the blades propelling at right angles to the sheet path to affect a thrust in a sideways direction to sheets moving in the direction along a sheet path. Hub 71 is driven through belts 75 which are driven by pulleys 77 which are mounted on a flexible shaft 79 which is driven through the main drive as will be described hereinafter.

To accomplish the offsetting of the sheet material into separately identifiable sets or booklets, there is provided a set separation assembly 80. Set separation assembly 80 includes a set separation finger 81 which is connected at one end of the pivot arm 83 and pivots on an axis through a stud 85. To move arm 83 there is a cam actuating mechanism 87 which includes cam element 88 and cam follower 89 which cam follower is connected to arm 83. Cam element 88 is carried on a cam shaft 91 which is driven through the main drive as will be described hereinafter. Cam element 88 is a single lobe cam having a recessed portion 93 which serves as a detent against cam follower 89. To ensure that the cam element 88 stops rotation after a single rotation, a cam portion 95 contacts a switch 97 which de-energizes a clutch mechanism 99 used to drive the cam element through the main drive. A spring 101 serves to maintain cam follower 89 into contact with cam element 88.

After the set indexing operation is completed, the set of sheet material is ejected by the set ejection assembly 105 comprising rollers 110 which are continuously driven on a shaft 112 and pivotal rollers 114 which serve as idler rollers mounted on a shaft 116 which shaft is mounted on support brackets 118 which pivot on the axis of a shaft 1 19. Mounted on support brackets 118 is a cam follower 121 which is driven by a cam element 123 which cam element is driven on the same shaft with the set separation assembly. Cam element 123 is driven through an electrical clutch 125 which is de-energized by switch 127 upon one revolution of the cam element which is thenarrested by the detent 129 to prevent further movement thereof. It will be noted that another switch 128 is positioned in the path of cam element 123 to de-energize electrical clutch 125 such that the copy gate is positioned open and remains open as will be explained hereinafter.

When clutch 125 is energized by a signal from machine control as will be explained hereinafter, the clutch turns cam element 123 which engages cam follower 121 which causes support brackets 118 to pivot on axis 119 until rollers 114 pinches the set against rollers 110. As cam element 123 continues to rotate, support brackets 118 are caused to pivot at the nip of rollers 110, 114 thereby enabling pivot axis 119 to float. When support brackets move on floating axis 119, the gate 69 is caused to pivot on supports 130 on a pivot 132. When this occurs, gate 69 is pivoted away from the sheet path enabling rollers 110 and 114 to drive the set into the receiving tray 120. It will be noted that the jogger assembly abuts with shaft 119 and is caused to move away from the sheet path during the time the set is being ejected. To facilitate the positioning of rollers 114 relative to rollers 110, support brackets are adjustable as by a screw (not shown).

The drive for the finishing apparatus is powered by a motor 150 which drives a main drive gear 152 which drives idler gear 154 which drives idler gear 156 and a gear 158 mounted on shaft 112. Gear 156 meshes with a gear 160 which drives a flexible shaft 79. Drivingly connected to shaft 112 is a gear 165 which drives an idler gear 167 which, in turn, drives a gear 169 to drive shaft 91 to actuate the set separation assembly and the ejection assembly through flexible coupling 170. Gear 169 drives gear 172 which, in turn, drives transport roll 64 through a belt 174 and pulley 175. Transport roll 64 is drivingly connected to roll 62.

MACHINE OPERATION The operation of copying machine with finishing apparatus according to the invention is best understood in connection with the wiring diagram of FIG. 16. The machine has different modes of operation wherein sets or books are produced in collation with the document input. Alternatively, if the document handling apparatus is dispensed with and documents are manually fed, copies are transported to the output tray with or without set separation.

For the set mode of operation, the copy sheets are advanced by transport 60 past jogger member to copy gate 69 which stacks them in registration. Signals are supplied from the set mode logic 201 to a flip-flop 205 when a set is completed. When a stop print operation is desired, a logic group 251 serves to supply a signal to flip-flop 205. When either of these situations occurs, a signal is supplied to a shift register 207 comprising flip-flops 209 which are arranged in three pairs. Shift register 207 receives input signals 211 from the processor logic and provides an output signal to gate 215. The output from gate 215 is stored in a flip-flop 217 which is coupled to a gate 219 which also receives a signal 221 from copy sheets along the sheet path as they are advanced to the copy gate. Gate 219 supplies an output signal to a flip-flop 225 for effecting set separation and also to a time delay 227 which after an appropriate time delay, supplies a signal to flip-flop 229. Flip-flop 229 provides an output to electrical clutch 125 through an amplifier 231 to actuate copy gate 69 after a complete set has been stacked. Time delay 227 ensures that electrical clutch 99 has been energized through flip-flop 225 and amplifier 235 to effect a set separation before the set is ejected into the output tray. It will be noted that switch 127 serves to supply a signal 237 to motor logic 240 which serves to de-energize the drive motor through an amplifier 241 if the processor has cycled out. Further, it will be noted that flip-flop 225 provides an output signal on alternate sequence only due to the insertion of a flip-flop 245 coupled between flip-flop 225 and flip-flop 229.

It will now be appreciated that the set separation assembly is actuated laterally for every other set. Thus, set separation from a previous set is achieved by side staggering alternate sets. Following set separation, the set is pinched by the rollers and 114 as the copy gate 69 is pivoted away upon actuation of the set ejection assembly. The collected set is lowered into the output tray where each set is staggered to distinguish between sets. The copy gate then closes and the rollers 114 return to its starting position ready to commence another set separation and collection cycle.

It will be appreciated that the finishing apparatus is also capable of transporting copies directly into the receiving tray without collection and set separation. In this case a signal 255 is received by flip-flop 229 in a switch 128 and a gate 257 such that the copy gate is positioned open and remains open while the rollers 1 10 and 114 are positioned together which serve toadvance the copy sheets directly into the output tray one at a time.

A jam logic 261 with detection sensors in the sheet path is coupled to the processor jam logic to supply a signal to the processor which supplies a signal 263 to motor logic 240 which serves to de-energize the drive motor in case of a jam occurring in the finishing apparatus.

What is claimed is:

- 1. Sheet paper stacking apparatus comprising transport means for advancing paper sheet material along a predetermined path,

rotatable paddle means positioned in the sheet path to contact the sheet material surface to impart a sideways movement to the sheet material,

gate means in the sheet path to arrest moving sheet material in a stack in corner registration therewith, said gate means being pivotable from a first position in the sheet path to a second position away from the sheet path,

stack eject means including pinching rollers associated with said gate means operative to engage the stack in a nip and eject it upon movement of said gate means away from the sheet path,

a receiving tray positioned in the sheet path to receive the stack ejected by said stack eject means, and

control means for moving said gate means from a position in the sheet path to a position out of the sheet path and then causing said stack to be ejected into the receiving tray after the gate means is moved to its second position.

2. Apparatus according to claim 1 wherein said paddle means comprises a plurality of blade members mounted on a hub rotated on shaft on an axis inclined at an acute angle to the plane of the sheet path.

3. Apparatus according to claim 1 wherein said control means includes circuit means for supplying signals operative to maintain said gate means away from the sheet path and said stack eject means in contact with the sheet path to advance sheet material directly from said transport means into the receiving tray continuously.

4. Sheet paper stacking apparatus comprising transport means for advancing paper sheet material along a predetermined path,

rotatable paddle means positioned in the sheet path to contact the sheet material surface to impart a sideways movement to the sheet material,

gate means in the sheet path to arrest moving sheet material in a stack in corner registration therewith, said gate means being pivotable from a first position in the sheet path to a second position away from the sheet path,

stack eject means associated withsaid gate means operative to engage the stack in a nip and eject it upon movement of said gate means away from the sheet path, receiving tray positioned in the sheet path to receive the stack ejected by said stack eject means, and control means for moving said gate means from a position in the sheet path to a position out of the sheet path and then causing said stack to be ejected into the receiving tray after the gate means is moved to its second position, said control means includes a continuously moving 

1. Sheet paper stacking apparatus comprising transport means for advancing paper sheet material along a predetermined path, rotatable paddle means positioned in the sheet path to contact the sheet material surface to impart a sideways movement to the sheet material, gate means in the sheet path to arrest moving sheet material in a stack in corner registration therewith, said gate means being pivotable from a first position in the sheet path to a second position away from the sheet path, stack eject means including pinching rollers associated with said gate means operative to engage the stack in a nip and eject it upon movement of said gate means away from the sheet path, a receiving tray positioned in the sheet path to receive the stack ejected by said stack eject means, and control means for moving said gate means from a position in the sheet path to a position out of the sheet path and then causing said stack to be ejected into the receiving tray after the gate means is moved to its second position.
 1. Sheet paper stacking apparatus comprising transport means for advancing paper sheet material along a predetermined path, rotatable paddle means positioned in the sheet path to contact the sheet material surface to impart a sideways movement to the sheet material, gate means in the sheet path to arrest moving sheet material in a stack in corner registration therewith, said gate means being pivotable from a first position in the sheet path to a second position away from the sheet path, stack eject means including pinching rollers associated with said gate means operative to engage the stack in a nip and eject it upon movement of said gate means away from the sheet path, a receiving tray positioned in the sheet path to receive the stack ejected by said stack eject means, and control means for moving said gate means from a position in the sheet path to a position out of the sheet path and then causing said stack to be ejected into the receiving tray after the gate means is moved to its second position.
 2. Apparatus according to claim 1 wherein said paddle means comprises a plurality of blade members mounted on a hub rotated on shaft on an axis inclined at an acute angle to the plane of the sheet path.
 3. Apparatus according to claim 1 wherein said control means includes circuit means for supplying signals operative to maintain said gate means away from the sheet path and said stack eject means in contact with the sheet path to advance sheet material directly from said transport means into the receiving tray continuously.
 4. Sheet paper stacking apparatus comprising transport means for advancing paper sheet material along a predetermined path, rotatable paddle means positioned in the sheet path to contact the sheet material surface to impart a sideways movement to the sheet material, gate means in the sheet path to arrest moving sheet material in a stack in corner registration therewith, said gate means being pivotable from a first position in the sheet path to a second position away from the sheet path, stack eject means associated with said gate means operative to engage the stack in a nip and eject it upon movement of said gate means away from the sheet path, a receiving tray positioned in the sheet path to receive the stack ejected by said stack eject means, and control means for moving said gate means from a position in the sheet path to a position out of the sheet path and then causing said stack to be ejected into the receiving tray after the gate means is moved to its second position, said control means includes a continuously moving drive mechanism engaging a cam member operative to move said gate means and actuate said stack eject means through a clutch mechanism actuatable in response to electrical signals. 